Hobby king multi star on offer

[Deleted member 4366]

They last ages if you don't use them.

 

[anotherkiwi]

Charger question:

My PSU is a 480 W model with 18 Amps on the +12 V output. Can I use one (1) PSU to power two (2) R/C balance chargers? My thought is one charger with parallel charging board/cables for 2 x 6S packs and another for 4S. I have an 80 W charger which has 7 Amps output which would be good enough for the 4S packs and looking at an 80 W 10 Amp charger for the 6S. 160 W needed and 17 Amps, I have 200 W and 18 Amps available (nominative of course... ).

I am not going to do/need bulk charging for the foreseeable future, I get home and recharge to storage voltage (if neccesary - the ride to Hendaye and back leaves cells at around 3.8 V so don't need to charge to storage voltage) and before setting out in the morning bring the packs up to 4.0-4.1 V per cell which takes about 50 minutes (per pack), time for breakfast, second breakfast and a quick collation... <hobbit smiley goes here>.

The second charger option is a multi-channel AC powered charger at around 100€ + shipping.

 

[motomech]

<<<<My PSU is a 480 W model with 18 Amps on the +12 V output. >>>
That doesn't really compute, does it?

12V X 18A = 226W

I am assuming you want to run a 80W & a 180W charger off that single power supply, so factoring in losses, you need at least 300 Watts.

<<< I am not going to do/need bulk charging for the foreseeable future>>>>
If, by that, you mean you are "breaking" your Lipo packs, you might want to rethink that. Breaking" the pack not only promotes wear and tear on the connectors and opens the door to nasty mistakes, it reduces the Lipo bricks natural tendency to work together.
Right now, I'm doing discharge "break-in" cycles on 20Ah of new Multistar and I'm seeing cell Voltages all over the place(but no bad cells). But, I know from experience, that if I leave my 12S/2P pack together, over time(cycles), the bricks will learn to play together nicely and the cells will fall into lock-step. By staying w/ the 80% D. of D. rule and leaving the pack intact, eventually, the number of straying cells will become less and less.
Lipo likes routine
Running 10S does have one major advantage, there are plenty of quality 300W balance chargers available, something that can not be said for 12S.
I've been thru many cheap charging solutions over the years to get to the reliable and fool-proof system I have now and I know would have been dollars ahead if I had just started w/ quality components. I'm also a fan of Battery Medics. For me, they are easier to use for checking and minor balancing than a balance board and a handfull of leads.

 

[Nealh]

All 6s nearly half price again, 16000mah 4 & 6s a bargain at the mo. 10s of 16000mah for £92 or 12s for £114. LIHV 4s 16000mah and 6s 10000mah reduced as well.

 

[anotherkiwi]

<<<<My PSU is a 480 W model with 18 Amps on the +12 V output. >>>
That doesn't really compute, does it?

12V X 18A = 226W

You are right I was having a Doh! moment mathematically. I'm feeling better now It is a computer PSU with a -12 V ramp etc. which makes the total of 480W.

I am assuming you want to run a 80W & a 180W charger off that single power supply, so factoring in losses, you need at least 300 Watts.

Another PSU is the best idea. Thanks. Another 80 W 10 Amp charger at 27€ was my plan.

<<< I am not going to do/need bulk charging for the foreseeable future>>>>
If, by that, you mean you are "breaking" your Lipo packs, you might want to rethink that. Breaking" the pack not only promotes wear and tear on the connectors and opens the door to nasty mistakes, it reduces the Lipo bricks natural tendency to work together.

I will be "breaking" them at the serial level only and charging the 2 packs in parallel. I am going to have to solder up parallel balance wires as they are on permanent "back order" at HK. I looked at parallel charging boards but as I only have 2 packs of each size they are overkill.

XT60's seem to prevent the mistakes and wear and tear issues. If the connectors get a bit iffy I can swap the series and parallel cables out at less than 3€ a pop. I have one XT60 that saw some heat in my only "incident" to date with a multimeter and the connection is still fine. They are so much better than bullet connectors - the ones on my controller were crap, one snapped off in the first week and the second one soldered itself together permanently.

I have a Battery Medic and will buy a couple more, Do you have a fan on yours? First time I tried balancing the 6S pack I thought I had fried it, it go very hot and the screen went black... Can I use two Battery Medics on the balance wires of packs that are connected in parallel, my guess is yes because all the cells will be at the same voltage give or take 0.02 V.

PS I have read several of you posts over on ES, you are one of my guides on the road to Lipo

 

[motomech]

I have a bunch of BM's, the older Blue ones that don't over heat and the new black ones that do. Unfortunately, the blues ones are no longer available.
I just received 4 of the 40 mm X 40 MM 24V fans that I will hot glue on the back of the BM and wire into an ext. for the full 22.5 Volts;

But I have found the black ones can be used in balance mode w/out over-heating. I also parallel 2 or 3 BM's for faster discharge;

They also seem to resist over-heating a little longer this way.

I make my own main wire "Y" adapters from #12 wire. It's kind of hard to solder the 3 wire junction w/ my 30 Watt iron, so I use a 4 mm bullet there;

I don't actually cut the wire that loops around, just strip off some insulation and fold the bare wire. I don't use a solder gun/iron when attaching 4 mm bullets either. I just use a sm. torch to fill the bullet's receiver cup w/ solder and push the striped wire in. I don't use the covers, just cover the bullet w/ shrink-fit. These adapters are longer than the ones from HK, but I like the #12 wire here.
Very easy

 

[anotherkiwi]

My first real world test has just ended: 118.8 km from a full charge on both batteries. 70 km on the Li-Ion battery and 48.8 km on the Lipos.

One of the cells in the 4S pack (#3) got out of balance (0.1V) and dragged the rest of the battery down below the 36 V cut off otherwise I think I was good for at least 55 km on the Lipo. At 36 V there is still plenty of juice left in the pack, I was pulling 460 W constant coming back up my steep homeward hill. Off the charger now back up to storage voltage the cells is within 0.02 V of the others, still the lowest cell in the pack.

 

[Deleted member 4366]

Lipos are getting close to empty at 3.6v. Be careful. A normal Li-ion ebike battery is nearly half full at the same voltage.

 

[anotherkiwi]

The LCD was showing 36.0-36.1 V but the alarm was screaming for the last 50 metres of the climb. When I checked that one cell was at 35.9 all the others at 36.0-36.1 V. At home on the Battery Medic the voltages were confirmed so cheap crappy HK alarms do have their use!

 

[motomech]

I have a bunch of BM's, the older Blue ones that don't over heat and the new black ones that do. Unfortunately, the blues ones are no longer available.
I just received 4 of the 40 mm X 40 MM 24V fans that I will hot glue on the back of the BM and wire into an ext. for the full 22.5 Volts;
View attachment 13694
But I have found the black ones can be used in balance mode w/out over-heating. I also parallel 2 or 3 BM's for faster discharge;
View attachment 13695
They also seem to resist over-heating a little longer this way.

I make my own main wire "Y" adapters from #12 wire. It's kind of hard to solder the 3 wire junction w/ my 30 Watt iron, so I use a 4 mm bullet there;
View attachment 13696
I don't actually cut the wire that loops around, just strip off some insulation and fold the bare wire. I don't use a solder gun/iron when attaching 4 mm bullets either. I just use a sm. torch to fill the bullet's receiver cup w/ solder and push the striped wire in. I don't use the covers, just cover the bullet w/ shrink-fit. These adapters are longer than the ones from HK, but I like the #12 wire here.
Very easy

Well, none of my Battery Medic dirt floor mods worked well.
Splitting a balance lead and running two BM's on the same bank of cells won't allow balancing. Each cell value bounces back and forth between the two BM's and won't stabilize.
The 24V mini fan won't run off the 22.4 V 6S brick. I'm using some 12V fans and they really hum. I can smell them so I don't think they will last long @ that Voltage. Still, at least the screen doesn't go black and they provide a faster discharge.
Turnigy has a new discharger/checker that is reported to work well;
http://www.hobbyking.com/hobbyking/store/__26136__Turnigy_DLUX_LIPO_Battery_Cell_Display_and_Balancer_2S_6S_.html
I'm liking my new Multistar pack more and more every day. The cells have stabilized and with my low powered system, see virtually no sag.
I was able to fit 20 Ah into a space that was previously filled to capacity with 10 Ah of regular 20C Lipo.

 

[anotherkiwi]

My 4S pack has a duff cell and has only been charged 5 or 6 times in 2 months... so out of guarantee It isn't too bad but I'm sure that it will get worse quickly. I wont be going below 3.7 V on that pack which is going to limit range a wee bit.

 

[Deleted member 4366]

That's fairly common. Even when new, you can expect the odd duff cell if you buy any quantity. If I need eight, I always buy 10, just in case.

 

[Nealh]

I was in need of a 12v field power supply for a piece of beekeeping equipment and SLA's are bit awkward and fairly heavy, so just got 2 x 3s X 5.2a lipo's to use in parallel as they were near half price and very very light in weight, another plus is that if I have an issue with any of my 6s's I can just put them in series to use as well on the emtb.

 

[anotherkiwi]

Even only having lasted that long it has so far only cost me 0.11€ a km. Which makes it cheaper than a bus ride to the station! (14 km and 2€)

And I will get a few more kilometres out of it before things become too hairy, for the moment we are looking at 0.2 V difference with the other cells when pushed to the limit.

 

[anotherkiwi]

Charged up the pack last night for today's use and put 8782 mA into the 4S and 8685 mA into the 6S so that is a wee bit over recommended 80% use. Setting alarms to 3.8 V

 

[Kinninvie]

Most of the capacity is at 3.7V so setting to 3.8V wont get you far at all!
By all means give it a try though as it will be interesting to see how far you get.
I set mine to 3.6V and this means I never have to balance my packs.

 

[anotherkiwi]

My mind was on the blink when I posted that, thats what you get to working nights... I meant to write 3.7 V but I wish I had an alarm that had 3.65 as an option. Looking at buying this one http://www.hobbyking.com/hobbyking/store/__48173__HobbyKing_8482_Cellmeter_6_Lipo_Life_Li_ion_Cell_Checker_Alarm_EU_Warehouse_.html

 

[Kinninvie]

that looks like it will do the job nicely.

 

[anotherkiwi]

As the Euro goes down against the Dollar HobbyKing prices rise, on items in stock...

We have pedelecs but our fuel prices are affected by currency fluctuations just like petrol in the local petrol station. How reassuring.

 

[KirstinS]

I know, battery are quite a bit more.

Just as I accidentally ruined a barely used 6s pack...